Set-screw.



R. E. NOBLE.

SET SCREW. APPLICATION FILED D3018, 1911. 1, 1 07,177, Patented Aug. 11,1914.

or dulled UNITED STATES PATENT OFFICE.

RALPH E. NOBLE, or CHICAGO, ILLINoIs, AssIeNoR T0 MORGAN-GARDNERELECTRIC COMPANY, or CHICAGO, ILLINOIS.

SET-S REW.

Application filed December a, 1911. Serial no. 664,560.

To all whom it may concern:

Be it known that I, RALPH E. NOBLE, a

combination or use forms one of the specialfeatures of my invention. Inmining machines having. cutter chains, or similar devices provided withcutting hits, it has been the ordinary practice to use set-screws forholding such bits in position. As these bits become dull it is necessaryto. loosen the set screws in order to remove them, andsuch changing ofbits may be necessary many times in a day. This frequent loosening andtightening of set screws causes the points or engaging ends to becomebattered unless such points or engaging end is suthciently hard.Heretofore, it has beenattempted to harden the points without hardeningthe whole screw, but it is an exceedingly diiiicult job, and the pointis apt to break oil. it the whole screw is hardened or tempered, it isapt to be too brittle, so that the screw head is liable to be broken offwhen the screw is tightened. in order to overcome these objections andto provide a screw which may have a strong, tough body portion with ahard unyielding point or engaging portion, and which may be usedrepeatedly without injuring the same, l have invented or discovered theimproved set screw'which is shown in the accompanying drawlngs.

in these drawings, Figure 1, is a side view of a set screw embodying myinvention, such screw having what is commonly known as a cup point andbeing partly broken away to show the interior construction; Fig. 2 is asimilar view of another screw showing-a sharp point orcone point; Fig. 3is another similar view showing a screw provided with a Hat point, suchas commonly used in con-' nection with lathe dogs; Fig. '4 is an endView of the screw shown in Fig. 1; Fig. 5

is a modification showing a flat point Fig. 6 is another modificationshowing an oval point; Fig. 7 is a further modifi- Specification of:Letters Patent.

Patented Aug. 11, 1914.

cation showing a point formed by means of a sleeve; Fig. 8 shows. aslight modification of a sleeve point; Fig. 9 is a further modificationshowing the point member as formed with a shank and shoulder; Fig. 10 isan end view of a chain link and bit showing the setuscrew in position;Fig. 11 is a side view of the-chain link.

-One of the principal features of my invention consists in providing aset screw which may be made of any material'mo-st suitable or desirablefor the construction of the screw and providing its engaging end with aplug or engaging portion of difierent material, best adapted to serveforthcpurpose of engagement with the part which the screw is adapted tohold.

As shown in Fig. 1, 12 indicates a set' screw, WhlCh for mining machinepurposes is preferably made of machine steelor'steel which issufficiently touglrand resisting so that the head, is "not apt to betwisted ofi, or the screw otherwise broken or injure in ordinary. use.The end of the screw is pro; vided with a hole or recess 13, into whichis fitted an engaging member or plug 14,

having a-cup point 15. This plug or engaging member is preferably madeto'fitv tightly'in the hole 13, and its inner end is made cone shaped inorder to fit the bottom of the hole 13, as such hole would ordinarily bemade by drilling into the end of the screw. On account oi? the plug'141- being.

given a driving fit, theside thereof may be flattened or grooved asindicated'at 16 to allow the air to ass out from'the hole as the plug isbeing forced into place.

The

walls l'I-of the set screw around the hole 13 are preferably leftsufiiciently thick and strongso that'they will not be bulged outordet'ormed by the engaging plug or point This is particularlydesirableas, it the- .threads are forced out or otherwise deformed at thisend, ofthe screw, it would be ditiicult to remove the screw or to again use it.The iglu'g or point 14 is preferably hardened suv ciently hard so thatit will engage with, and cut into the surface of the bit or other artwhich it is adapted to hold in place, wit out injury to itself. I

As shown in Fig; 2," the screw 18 is provided at its engaging end with aslightly tapered hole 19, having a flat bottom which is adapted toreceive the correspondingly tapered sharp pointed engaging member 20.

The screw 21, shown in Fig. 3 is provided at'its engaging end with ahole or recess 22, corresponding with the one shown in Fig. 1, but theengaging plug or member 23 ismade with a fiat or dog point. The screw24, shown in Fig. 5 is recessed at its lower end to receive a flat pointengaging member 25. The screw 26 shown in Fig. 6 is shown with an ovalpointed engagingpiece 27 as indicated.

In Fig. 7, the screw 28 instead of being recessed, is turned down at itsengaging end to form a shouldered extension 29. Around the extension isfitted the engaging ring or member 30 which fits closely over theextension, and has its inner end resting against the shoulder on thescrew, while its outer end is sharpened as indicated at 31, for engagement with the article to be held. In this instance the engagingmember 30, is preferably hardened and in order to temper the same'andalso secure it in position, I prefer to heat it and place it in positionand treat it so that it will be shrunk in place and tempered at the sametime.

The screw 32 shown in Fig. 8 is provided with an engaging ring or sleeve33, similar to that shown in Fig. 7, but sharpened by beveling in theopposite direction.

The screw 34 shown in Fig. 9 is provided at its engaging end with a hole35, which is preferably made smaller than in the ones shown in thepreceding figures which leaves a thicker wall for the same sized screwand also a substantial shoulder 36 at the end of the screw. The engagingplug or member 37 is provided with a shank 38, fitting within the holeand with a shoulder 39 adapted to press against the shoulder-.36 or endof the screw as lndicated. This engaging meniher is shown with a cuppoint, but obviously anyhdesired form ofpoint may be used therewit.

While in most instances I prefer to make the screw of comparativelytough non-brittle material, and the point or engaging member of hard ortempered materia such as tern pered steel, yet in some instances, aswhere the set screw is to hold a piece of finished material, such asshafting and it is desired not to injure the same, I may malre the engaging point or inset of comparatively soft material, which may bepressed closely in engagement with the article to be held withoutinjuring the same.

As above indicated one of the prmclpal uses of my improved set screw isin connection with mining machine chains. A l nk 40 of one of suchchains is shown in Flgs. 10 and 11, having a bit 41 inserted thercm inthe usual manner, and providedwith a set screw 12, embodying myinvention. It will be observed that by means of this arrangement, theset screw may be used repeatedly without liability of being broken orhaving its engaging end fiatened or batteredout, so as to injure thethreads, as frequently occurs when such engaging end or point is notmade sufficiently hard.

From the above description it Wlll be observed that my invention may beembodied in various different forms of set screws and I do not wish tobe limited to the exact forms shown and described, except in so far asspecified in the appended claims, but

What I claim and desire to secure by Letters Patent is:

1. A set screw comprising a threaded body portion formed of iron or softsteel and having a head at one end and a hole 1n the opposite end, and ahardened steel point fitting tightly within said hole.

2. A set screw having a soft steel threaded body portion with a head atone end and shaped at the opposite end for receiving a point or engagingmember, and a hardened engaging member tightly secured to said oppositeend.

3. The combination with'the barrel portion of a set screw having a holein the end thereof, of an engaging point or member of extremely hardsteel having a shank fitting in said hole, and having a shoulder fittingagainst the end of the barrel.

RALPH E. NOBLE.

Wi tnesses WV. R. CUMMINGS, Geo. M. Lorr.

